jim mcfarland was doing the dimpling deal back in the day when he was with edelbrock
intake ports and combustion chambers,its nothing new i personally like the burr finish that * does on his cylinder heads

Velocity changes within a port make for pressure changes.
Pressure changes make for fuel drop out.
Drops of fuel love to cling to a smooth surface and not break back up into finer easy to burn state no less vaporize!
This makes for more fuel being needed to make a given level of power and can lead to fuel wash on the cylinders walls and fast waring rings and Bores.

To prove this happens just place a drop of water on a stone kitchen counter top and then blow on it.
All the water does is stay in a ball, but move around the counter top.
Next place a drop OD water on some 80 to 120 grit sand paper and blow on it, now you will see the ball of water break up into a mist , or at least far finer drops!

smooth or rough, that fuel is on the walls of the manifold/ports, period.

The finer the fuel droplets are (better atomized) in the combustion chamber the faster and more completely they burn. This creates more power out of the same amount of fuel and less emissions because there is less raw and unburnt gas running out of the exhaust.

The fuel puddling is seen very easily in EFI systems with datalogging. In fact, the best systems use OEM-style "wall-wetting" transient algorithms to account for the dynamic conditions that affect addition to and subtraction from the "puddle."

Ever take a high mileage Ls head apart? You can see the pattern on the port walls where the fuel is spraying and "pressure" washing the port walls, the rest of port usually has a suprising amount of carbon and gook built up on them.

If there was anywhere this would be beneficial a high speed ssr comes to mind. If surface texture would help the air stay attached at higher speed before separation that would make a ssr that is shape challenged perform better.